Foldable keyboard

ABSTRACT

A portable foldable keyboard comprised of two housings, each of which contains a key assembly, and a central hinge. The two housings can be slid together when the keyboard is unfolded and they interlock to form a sturdy keyboard having the standard QWERTY keyswitch layout.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a foldable keyboard, and moreparticularly to a foldable keyboard that is easy to manufacture and thatis sufficiently rigid when unfolded such that it can be utilized whileit is positioned on a user's lap. Keyboards embodying this invention areparticularly useful when combined with personal data assistants(“PDAs”).

DESCRIPTION OF RELATED ART

[0002] The need exists for a PDA sized, efficient, low cost portablekeyboard. Although several versions of foldable or portable keyboards,which are useable with PDAs, have been patented or introduced into themarket, none of the existing keyboards satisfy the need for a PDA sized,efficient, low cost portable keyboard. Each of the existing keyboardsexhibits one or more of the following drawbacks: they are substantiallylarger than a PDA even when folded; their unfolded length extendssubstantially beyond the useable keyswitch area; the keyswitch layoutsdo not comply with the standard QWERTY keyswitch layout used by mostU.S. keyboards; they are overly complex and consist of many parts; andthey lack sufficient rigidity for efficient lap-top use.

[0003] For example, U.S. Pat. No. 5,941,648, discloses a foldablekeyboard that can be used with a PDA. The keyboard disclosed in U.S.Pat. No. 5,941,648 is divided into curved halves connected together by asingle hinge. When this prior art keyboard is unfolded for use, itskeyswitch layout is not in conformance with the standard QWERTYkeyswitch layout. Additionally, it is not sufficiently rigid to be typedon when in a user's lap. Further, the keyboard disclosed in U.S. Pat.No. 5,941,648 is substantially larger than a PDA even when it is folded

[0004] The Stowaway Portable Keyboard, which is sold by Think Outside,Inc., discloses a foldable keyboard having four segments connectedtogether by three hinges. Each segment is comprised of a housing and akeyswitch assembly. When the Stowaway Portable Keyboard is unfolded agap exists between the keys on the first segment of the keyboard and thekeys on the second segment and a gap exists between the keys on thethird segment of the keyboard and the keys on the fourth segment. Thekeyswitch assemblies may be slid together to close the gaps between thekeys and to place the keyswitches into the standard QWERTY keyswitchlayout. However, the housings are not slid together. Accordingly, asubstantial amount of unused space exists on the outer sides of thefirst segment of the keyboard and the second segment of the keyboardmaking the keyboard unnecessarily long. Additionally, a keyboard havingfour segments and three hinges is difficult to manufacturer and requiresa large number of parts, which results in a high manufacturing cost.

SUMMARY OF THE INVENTION

[0005] Embodiments of this invention provide an efficient, low costportable keyboard that can be used with a PDA as well as other portablemicroprocessor based equipment. The preferred embodiment of thisinvention is a keyboard separated into two halves, which can be foldedtogether when the keyboard is not in use. When the keyboard is folded,the keyboard is approximately the size of a PDA and it can be carried ina user's pocket. When the keyboard is unfolded, the two halves can beslid together using a unique sliding interlock mechanism. This uniquesliding interlock mechanism, which requires only a few parts and is easyto manufacture, allows the two keyboard halves to form a single keyboardthat does not flex in the middle and that has a sturdiness similar tothat of a one piece keyboard. Additionally, when the two halves of thekeyboard are slid together, the keyboard's keyswitches are in a standardQWERTY keyswitch layout and the width of the keyboard does not extendbeyond the useable keyswitch area.

[0006] Additionally, the preferred embodiment of this invention utilizesa key membrane cable, which transmits electrical signals from thekeyswitches, that utilizes a folded region to facilitate sliding the twokeyboard halves together and apart.

[0007] Further, the preferred embodiment of this invention utilizes aPDA connector that automatically pops up when the keyboard is unfoldedto facilitate connecting a PDA to the keyboard.

[0008] These and other objects, features, and advantages of the presentinvention will become more apparent in light of the following detaileddescription and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present invention will be more easily understood withreference to the following drawings.

[0010]FIG. 1 is an exploded top view of the preferred embodiment of thepresent invention.

[0011]FIG. 2 is a is a top view of the preferred embodiment of thepresent invention in its closed condition.

[0012]FIG. 2A is a side view of the preferred embodiment of the presentinvention in its closed condition.

[0013]FIG. 3 is a top view of the preferred embodiment of the presentinvention in its open non-interlocked position.

[0014]FIG. 3A is a side view of the preferred embodiment of the presentinvention in its open non-interlocked position.

[0015]FIG. 4 is a top view of a hinge plate used in the preferredembodiment of the present invention showing two key membrane cables.

[0016]FIG. 5 is a top view of the preferred embodiment of the presentinvention in its open interlocked position.

[0017]FIG. 5A is a side view of the preferred embodiment of the presentinvention in its open interlocked position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0018] A description of a preferred embodiment of the present inventionwill now be given.

[0019]FIG. 1 shows an exploded top view of a keyboard embodying thepresent invention. The keyboard is comprised of a right housing 1, aleft housing 2, a right hinge plate 3, a center hinge 4, hinge pins 5,right key assembly 6, left key assembly 7, key membrane cable 8, PCBmembrane cable 9, PCB 10, PCB housing 11, PDA membrane cable 12, PDAconnector 13, PDA connector holder 14, screws 15, PDA support 16, PDAsupport wire 17, and locking latch 18.

[0020] Right hinge plate 3 is positioned in right housing 1 and rightkey assembly 6 is positioned above right hinge plate 3 in right housing1. Screws 15, which are inserted from the bottom of right housing 1,pass through elongated openings 20 in hinge plate 3 and into right keyassembly 6. Left key assembly 7 is inserted into left housing 2 andaffixed thereto through the use of screws 15. Center hinge 4 isconnected to right hinge plate 3 and left housing 2 through the use offour hinge pins 5. Locking latch 18 is affixed to the outer side of lefthousing 2 through the use of two pins 25. PDA support 16 is slidablyinserted into left housing 2 and PDA support wire 17 is rotatablymounted into PDA support 16. Key membrane cable 8, which transmitselectrical signals from the keyswitches 19, is connected to the left keyassembly 7 and the right key assembly 6. PCB membrane cable 9, whichtransmits electrical signals from the keyswitches 19 to the PCB 10, isconnected to left key assembly 7. PCB 10 is affixed to left housing 2and it is held in place by PCB housing 11 through the use of screws 15.PDA membrane cable 12 is connected to left key assembly 7 and to PDAconnector 13, which is mounted inside of PDA connector holder 14. PDAconnector holder 14 is rotatably mounted in PCB housing 11.

[0021] A PDA or other portable microprocessor based equipment can beconnected to the keyboard through the use of PDA connector 13. When aPDA is connected to the keyboard, PDA support 16 should be positioned inits extended position as shown in FIG. 5 and PDA support wire 17 shouldbe rotated to its upright position as shown in FIG. 1. PDA support wire17 provides support for the connected PDA and PDA support 16 maintainsPDA support wire 17 in its upright position against the weight of thePDA. When a PDA is not connected to the keyboard, PDA support wire 17should be rotated to its lowered position and PDA support 16 should bepositioned in its inserted position as shown in FIG. 3.

[0022]FIG. 2 is a top view of the keyboard in its closed condition andFIG. 2A is a side view of the keyboard in its closed condition. Thekeyboard is closed by folding right housing 1 over left housing 2 orvice versa. Center hinge 4 rotates about left housing 2 and righthousing 1 rotates about center hinge 4. Accordingly, in the closedcondition, center hinge 4 is perpendicular to both left housing 2 andright housing 1. Locking latch 18 latches onto right housing 1 tosecurely fasten the two halves of the keyboard together.

[0023]FIG. 3 shows a top view of the keyboard in its opennon-interlocked position and FIG. 3A shows a side view of the keyboardin its open non-interlocked position. The keyboard is opened byunfolding right housing 1 from left housing 2. Center hinge 4 rotatesabout left housing 2 and right housing 1 rotates about center hinge 4.Accordingly, in the opened non-interlocked condition, center hinge 4 isin the same plane as and in between left housing 2 and right housing 1.Additionally, the left edge of right hinge plate 3, which is connectedto center hinge 4, is coextensive to the left edge of slidable extenderportion 21 of right housing 1. The right edge of right hinge plate 3 isinset from the right edge of right housing 1 by a distance at leastequal to the length of slidable extender portion 21 of right housing 1.

[0024]FIG. 4 shows right hinge plate 3 and it shows the two key membranecables 8. The key membrane cables 8 have a folded area 22 in the cut outslot of right hinge plate 3. This folded area stores extra cable lengthto allow sliding of key assembly 6 and right housing 1 into openinterlocked position & open non-interlocked position. The amount of foldin the folded area 22 is at its maximum when the keyboard is in its openinterlocked position, is at its minimum when the keyboard is in itsclosed condition, and is intermediate when the keyboard is in its opennon-interlocked position.

[0025]FIG. 5 shows a top view of the keyboard in its open interlockedposition and FIG. 5A shows a side view of the keyboard in its openinterlocked position. The keyboard is changed from the opennon-interlocked position to the open interlocked position by sliding theright housing 1 and the left housing 2 together. Slidable extenderportion 21 of right housing 1 extends past center hinge 4 and slidesover a portion of left housing 2. Additionally, when the two halves ofthe keyboard are slid together, right hinge plate 3 slides inside righthousing 1 such that the right edge of hinge plate 3 is adjacent to theright edge of right housing 1 when the keyboard is in its openinterlocked position. Accordingly, the right edge of center hinge 4 iscontiguous with the left edge of right key assembly 6, except that thehinge portions of right hinge plate 3 extend between center hinge 4 andright key assembly 6. In the open interlocked position, the keyswitches19 of the keyboard are in the standard QWERTY configuration and no partof right housing 1 or left housing 2 is not covered by either right keyassembly 6 or left key assembly 7.

[0026] As shown in FIG. 1, PDA connector 13 is mounted inside PDAconnector holder 14 and PDA connector holder 14 is rotatably mounted inPCB housing 11. This rotatable mounting is accomplished by insertinginsertion pin 23 of PDA connector holder 14 into opening 24 of PCBhousing 11. Insertion pin 23 and opening 24 are manufactured such thatthey elastically deform when PDA connector 13 and PDA connector holder14 are pressed down parallel with the top of PCB housing 11, such ashappens when the keyboard is placed into its closed position. Thiselastic deformation causes a resilient force to be applied to theconnector holder 14, thereby, causing connector holder 14 and PDAconnector 13 to rotate upward (pop up) when the keyboard is opened.

[0027] The drawings and descriptions of the preferred embodiment aremade by way of example rather than to limit the scope of the inventions,and they are intended to cover, within the spirit and scope of theinventions, all such changes and modifications within the spirit of theinvention.

1-10. (canceled)
 11. A PDA connecting device for a portable keyboard comprising: a PDA connector; and a means for resiliently and rotatably mounting said PDA connector to said keyboard.
 12. A PDA connecting device for a foldable keyboard comprising: a PDA connector holder; and a PDA connector; wherein said PDA connector is mounted in said PDA connector holder such that said PDA connector pops up when said foldable keyboard is unfolded.
 13. A key membrane cable for a foldable keyboard comprising: a straight region of said cable; and a folded region of said cable. 